Roller-clutch lifting-jack.



. F. STARR.

ROLLER CLUTCH LIFTING JACK.

- APPLICATION FILED FEB. 24, 1914.

1,174,363. Patented Mar. 7,1916.

. untrue s'rawnnr WERE FRED STARR, OF SACRAMENTO, CALIFORNIA.

ROLLER-CLUTCH LIFTING-JACK.

Specification of Letters Patent.

Patented Mar. 7, 1916.

Application filed February 24, 1914. Serial No. 820,547.

To all whom it may concern:

Be it known that I, FRED STARR, a citizen 7 This invention relates to improvements in.

lifting jacks, and has for its object the provision of such a device having the novel features of construction and operation,'as hereinafter set forth.

The invention is illustrated in the accompanying drawing, in which,

Figure l is a perspective view of the improved jack, a portion of the casing of the same being broken away to show the interior mechanism; Fig. 2 is an enlarged view of the upper extremity of the jack showing more clearly the releasing mechanism Referring to the drawing, the frame of the jack is indicated at A, and may be of any appropriate shape and construction suitable for housing the operative parts of the jack. Slidably mounted in the casing A is the lifting bar B, provided at its lower extremitywith a projecting toe 0, adapted to support, raise or lower a weight when the bar B is actuated. The casing A is provided with an opening V to accommodate the toe C. The upper extremity. of the barB is provided with a cap C secured to the said bar by any suitable means, such as the screw E. The cap D, in the lowermost position of the barB, abuts the top of the casing A, and

4 thereby prevents further downward movement of the bar with respect to the casing. The cap D also constitutes a supporting head for the object to be acted upon by the 'ack.

] Situated interiorly of the casing is a block F, preferably of metal and provided with a recess adapted to accommodate the bar B. The provision of the recess forms an arm G, which engages the outer surface of the bar B. The inner surface of the recess in block F facing the inner surface of the bar B is inclined, as'shown at F. A plate M, secured to the top of the block F, is provided with an opening L through which a wire K is passed and bent at its upper extremity over the surface of the plate M to prevent the same from slipping through said opening. The lower extremity of the wire, K supports a roller H in any suitable manner, such as by providing said roller with a circumferential groove, in which the looped extremity of the wire K is adapted to engage.

A coiled spring 0, preferably conical in shape, is interposed between the plate M and the roller H, and tends to force the latter downwardly between the inner face of the bar B and the inclined surfaceF. above-described manner of mounting the roller H is merely exemplary, as obviously the same can be mounted in numerous ways to produce the same result.

A plate X may be secured to the side of interior mechanism thereof.

A handle socket P is pivotally mounted on .the casing 1A, preferably by means of a The the block F'to constitute'a closure for the bolt B and cooperating nut S. The said socket is provided with a heel portion Y adapted to engage in an appropriately formed opening in the block F,- whereby pivotal movements of the socket P around the axis R will produce longitudinal movements on the block F. The socket P is provided with a suitable recess Q, in which the actuating lever may be inserted.

Mounted. on the casing 1 and. projecting into the lower portion of the recess in the block F is anextension T, constituting a trip for the roller H, as will be hereinafter described. a l p The upper part of the casing is provided with an inwardly projecting'portion 1 presenting an inclined surface similar to-that provided on the block F. A roller 2 is in terposed between such inclined surface and the inner'surface of the bar B, and is supported in a manner similar to that described in connection with the roller H, to wit, by a wire 12, the lower extremity of which is looped around the body of the roller and engages in a peripheral recess 9. I

The upper extremity of the wire 12 passes through an opening 6 in a removable cover plate 14: held in place by a screw 10, and is looped, as shown 'at 12, to engage the cross pin 7 of a pivoted releasing lever 3. The said lever 3 is pivoted to standards 4, 4, as

clearly shown in Fig. 2 at 5, 5. The cross the lever, so that when the outer extremity of the lever 3 is depressed, the pin 7 is raised, thereby lifting the supporting wire 12 and the roller 2. A spring 11 similar to that used in connection with the roller H reacts at one extremity against the bottom of the plate 14, and at its other extremity against the roller 2, thereby holding the roller 2 in its lowermost position, and the outer extremity of the lever 3 in its raised position.

The operation of the apparatus is as follows:A downward force applied to the actuating handle in the socket P raises the block F, and the inclined surface F thereof wedges the roller H between the same and the inner surface of the bar B. The said surface F, roller H, and arm G cooperate in gripping the bar, and an upward movement of the block F therefore, results in an upward movement of the bar B. As the actuating lever is raised and the block F lowered, the bar B in tending to lower, wedges the roller 2 between the inclined surface of the portion 1 and the inner face of the bar B. The bar B is thereby prevented from lowering and is held in the position to which it was elevated by the raising of the block F. When the block F lowers with the raising of the actuating lever, the inclined surface F, roller H, and arm G are inoperative, since no wedging action of the roller H results on a downward movement of the block F. The next downward movement of the actuating lever will cause the block F, roller H, and arm G to grip the bar B at a lower point, and the liftin action, as above described, will be repeated, the projecting portion 1 and roller 2 serving at each actualowered.

' loosening the roller 2. The lever 3 is then depressed, which elevates the roller 2, and prevents a wedging action between the same and the projection 1, when the bar B is The actuating lever is then raised,

thereby lowering the block F. As the roller 2 is held in its raised position, the bar B is free to lower with the block F. As the roller H lowers with the block F, the projection T engages the same, and thereby trips the roller to permit further downward movement of the bar B.

Obviously,many modifications and changes can be made in the details of construction, without departing from the spirit of the invention, as defined in the accompanying claim.

What I claim is 1- A lifting jack comprising a casing, a slidable lifting bar mounted therein, an actuating block slidably mounted on said bar, said block presenting an inclined surface to one face of said bar,'a roller interposed between said inclined surface and said face of the bar and provided with a circumferential recess, a wire engaging in said recess and supported at its upper end from said block, a spring encircling said wire and tending to wedge said roller between said inclined surface and the face of said bar whereby the bar is lifted unitarily with the block when the latter is raised but permitted to remain stationary when the block is lowered, means to raise and lower said block, an element presenting a second inclined surface to said bar, a second roller interposed between said surface and one face of said bar and provided with a circumferential recess, a wire engaging in said recess, a trip lever to which the upper end of said wire is connected, and a second spring encircling said last-named wire tending to wedge said roller between said surface and said face of the bar whereby said bar is held stationary when the block is lowered.

In testimony whereof I affix my signature, in presence of two witnesses.

FRED STARR. -Witnesses A. M. AUBERTos, WM. B. THOMAS.

Copies of this patent may be o'ntained for five cents each, by addressing the Commissioner of Patents,

Washington, D C. a 

